In a large number of today's applications, such as for example biotechnology applications or material characterisation, spectroscopy is used as a routine tool for performing absorbance and fluorescence and Raman measurements. For example in bio-sensing applications, molecular diagnostics or pharmacological applications, often a number of samples are processed in parallel, in order to increase the processing speed. An example of so-called high-throughput screening is the application of multi-well plates with a high number of sample reservoirs, ranging from 96 to 384 and even higher.
With the increasing number of wells in these plates, processing a whole plate in a serial way becomes too time-consuming and a parallel way of processing becomes necessary. The most obvious way to conduct a spectroscopic measurement on several samples simultaneously is to provide each sample with its own spectrometer. Even the smallest spectrometers available today will make such a setup rather large and difficult to assemble. Various samples can also be studied simultaneously by using hyperspectral imaging, in which, typically a one-dimensional image is transformed into a two-dimensional spectral image. When there is a minimal distance between two samples such a setup results in a poorly filled field of view of the hyperspectral imager and the hyperspectral imager must be dimensioned for the entire sample row, making the imager large.
In a classic Czerny-Turner configuration, typically one mirror is used to collimate light coming from an entrance slit and direct it towards the reflection grating. After diffraction, a second mirror is used to focus the light onto the detector or an exit slit. Sometimes both mirrors are combined into one mirror in which the configuration is also called an Ebert-Fastie configuration.
U.S. Pat. No. 6,862,092 B1 describes a system and method for measuring spectral information of light from at least one object. The system describes the use of a transparent body, whereby a light beam enters the transparent body and guides the diverging light beam via two mirror reflections on a diffractive optical element. The diffracted light beam then is reflected at an aspheric mirror surface and is directed to a detector element 34, allowing to detect spectral information. The transparent body typically has a complex, non-standard lens shape.